1. Field of the Invention
This invention relates to a door machine mechanism, more particularly to a door machine mechanism for a rolling door having fireproof, smokeproof, and escape functions by which the rolling door can be opened in a reverse direction by a one-way transmission device.
2. Brief Description of Prior Art
Generally, rolling door can be cataloged as fire doors, smokeproof doors, emergency doors and escape doors according to their usage, function and purpose. The conventional fire doors or the smokeproof doors are classified into two types based on their operational mode: one type is failsafe mode, and the other type is a non-failsafe mode. In the case of the failsafe mode, a brake is immediately released to let the rolling door move downward by its own weight and close, if electric power is interrupted, no matter what the cause of which is. However, if the electric power is not interrupted on a firing, the electric power will be cut out by, for example, smoke detector, temperature sensor or other fire detecting devices, or is cut out mechanically by fusible link devices, in which a fusible metal will be melted by fire. Hence the brake is released to close the rolling door by the way as stated above. On the other hand, for the non-failsafe mode, the rolling door is not closed immediately after an interruption of electric service. Only after an occurrence of firing is detected by, for example, smoke detector, temperature sensor or other fire detecting device, and a short duration of electric current from a spare power source, such as capacitor, battery or the like, is fed for releasing the brake for a short time period, or fusible link devices for mechanically releasing brake are melted due to high temperature of fire, the rolling door moves downwardly and closes by its own weight. The above-mentioned fire door and smokeproof door generally have equipped with a manual operation mechanism, such as a hand chain wheel with an endless chain, to drive a transmission mechanism of the rolling door. If the cause of the interruption of electric service is not due to firing and the rolling door is needed to be opened, or the cause is due to firing and the rolling door must be opened for fire escape, the rolling door can be lifted up by driving the hand wheel through an exertion on the endless chain. When the rolling door must be opened for emergent escape in case of firing, much time and physical effort have to be consumed for opening the rolling door by manual operation, which will render vital delay of escaping.
However, a design of emergency door or escape door is contrary to that of fire door in usage and function, i.e., the fire door should be maintained to be unimpeded or easily opened in a power interruption condition. Therefore, for manufacturing industries, a variety of door machine mechanisms have to be developed to cope with different demands based on location for installing a door machine mechanism, desired function and purpose. Not only time required for development for a machine mechanism is long, production cost is high, but also number of parts is high, and hence which may cause their production process becoming complicated and high inventory.
A lot of relevant patents concerning door machine mechanism of fire door have been proposed, such as U.S. Pat. No. 5,673,514, U.S. Pat. No. 5,893,234, U.S. Pat. No. 5,203,392, and U.S. Pat. No. 5,386,891. Basically, for the above patents, a rolling door slides downward to shut a door by its own weight of gravity under a power interruption condition so as to block thick smoke or raging flame from scattering. Further, in the above patents, the rolling door can be lifted up directly by hands without using a hand chain wheel and endless chain as described above. However, using physical force to resist against the weight of the rolling door to open the door will consume enormous physical effort, which especially is too difficult for feeble men.